Sedona, try to compare features added to the class-D modules within each amp to have an idea of what it may sound like and whether the asking price is commensurate with the finished product. Out of the box, class-D modules are relatively inexpensive and generally do not sound that great. Additional parts and circuits built around the modules can improve the sound but can also increase the cost substantially. On the other hand, features that add to the cost with dubious effect on the sound are a waste of money. Here are just some of the areas to check:
1. Out of the box, the frequency responses of class-D modules are different and far from flat. For example, the ICE 500 is worse than the ICE 250 but both are not optimally flat. If nothing is done to improve this frequency response, the amp may sound dynamic but not very pleasant.
2. Class-D modules are susceptible to RF that can make the amp sound awful. Is anything done (such as transformer coupling at the input) to prevent RF from getting into the amp?
3. The ICE modules, like all class-D modules, radiate EMI that can create havoc with the amps sound. Did the designer do anything to keep module EMI from affecting the rest of the amp?
4. The power supply affects the sound but the problem may be more complicated than we think. Analog power supply (toroidal transformer and capacitors) seems to sound better than switching power supply; dual mono operation (to prevent inter-channel modulation) seems to also improve the sound. But I am not sure if and why the highly efficient class-D modules need a very stiff power supply. Maybe they do. Well learn more about that with time and experience.
Prices and values are not the same. If someone just sticks a class-D module inside a box off the shelf, the amp should not cost very much and not much should be expected from its sound. On the other hand, not all expensive parts built around the modules serve to improve the sound. Some may serve only to impress gullible buyers. You should critically compare design features, construction quality, and price and then try to listen to the amp first before buying.
1. Out of the box, the frequency responses of class-D modules are different and far from flat. For example, the ICE 500 is worse than the ICE 250 but both are not optimally flat. If nothing is done to improve this frequency response, the amp may sound dynamic but not very pleasant.
2. Class-D modules are susceptible to RF that can make the amp sound awful. Is anything done (such as transformer coupling at the input) to prevent RF from getting into the amp?
3. The ICE modules, like all class-D modules, radiate EMI that can create havoc with the amps sound. Did the designer do anything to keep module EMI from affecting the rest of the amp?
4. The power supply affects the sound but the problem may be more complicated than we think. Analog power supply (toroidal transformer and capacitors) seems to sound better than switching power supply; dual mono operation (to prevent inter-channel modulation) seems to also improve the sound. But I am not sure if and why the highly efficient class-D modules need a very stiff power supply. Maybe they do. Well learn more about that with time and experience.
Prices and values are not the same. If someone just sticks a class-D module inside a box off the shelf, the amp should not cost very much and not much should be expected from its sound. On the other hand, not all expensive parts built around the modules serve to improve the sound. Some may serve only to impress gullible buyers. You should critically compare design features, construction quality, and price and then try to listen to the amp first before buying.